In Florida, Mr. Zimmerman was originally released without charges because police, referencing the stand-your-ground law, found no reasonable cause to disbelieve Zimmerman’s self-defense claim. The state only charged Zimmerman after the governor, under a storm of criticism, appointed a special prosecutor to investigate.

The Texas verdict shows, some say, that the legal process can weed those who attempt to abuse the law, with courts retaining significant power to determine appropriate use of force even in states where there’s no "duty to retreat."

“What the Texas case says is you have to take each state law and each fact pattern on its own terms and you can’t make sweeping generalizations, as many opponents of stand your ground laws have, that this is a license to kill – it’s clearly not,” says Cornell University law professor William Jacobson, who runs a conservative blog at Legal Insurrection.

Statistics indicate, however, that the stand-your-ground defense is generally effective. In Florida, about 70 percent of stand-your-ground defenses – which have grown in number annually since Florida passed the first version of the law in 2005 – are successful. Nationally, homicides are twice as likely to be ruled justifiable in stand-your-ground states.

While the Florida law, for instance, wasn’t intended to protect criminals in the commission of a crime, it has protected defendants involved in gang shootings and drug deals gone bad, as well as defendants who shot and killed someone retreating from an altercation.